Steampunk Mrs. Foster

Steampunk Mrs. Foster is a character that you can unlock by earning Summer Sideshow related achievements, Objective Mode and Wave Mode achievements, and the Punk'd achievement as stated in the Bio below.

In one of the perverse paradoxes created by weird alternate realities, that place where day traders are hip and trendy seems to have the same effect on their slightly-warped commodity-trader girlfriends. Now who would have guessed that?